Experimental and numerical study of long term sedimentation in a secondary channel: example of the Beurre island on the Rhône River, France

B. Camenen (1) , E. Andries (1) , J.B. Faure (1) , M. de Linares (2) , F. Gandilhon (2) , G. Raccasi (3)

1 UR HHLY - Hydrologie-Hydraulique
2 aucun
3 aucun

Two numerical models (1D and 3D) have been used to reproduce significant deposits that have been observed in two secondary channels located next to the Beurre island on the Rhône River, France. Both models yield relatively good results compared to the measurements but are sensitive to the upstream boundary condition for the concentration, which is poorly understood. Several issues also arose thanks to this modelling. Computation of discharge repartition in the two secondary channels appeared to have a strong impact on long-term estimation of fine sediment deposits, and is an interesting challenge for 1D modelling. Discharges in the Rhône River above the one year return period flood yield approximately 50% of the fine sediment mass transiting in the secondary channels, which represents approximately 1% of the total SSM fluxes. And 1 to 10% of these fine sediments appeared to settle down. Also, erosion and deposition laws that are implemented in 1D and 3D models induce different strategies for calibration and validation.

Mots clés: OHM VALLEE DU RHONE; RHONE COURS D’EAU; LABEX DRIIHM; TRANSPORT SOLIDE; OBSERVATOIRES HOMMES-MILLIEUX; SEDIMENTATION; MODELE NUMERIQUE

Domaines: Sciences de l'environnement

B. Camenen, E. Andries, J.B. Faure, M. de Linares, F. Gandilhon, et al.. Experimental and numerical study of long term sedimentation in a secondary channel: example of the Beurre island on the Rhône River, France. International Symposium on River Sedimentation, Sep 2013, Kyoto, Japan. 8 p. ⟨hal-00926113⟩